The image shows a dandelion in the middle, but I'm asking about the plant in the background.
This carpet type weed/flower is growing in my backyard. The flowers are very tiny and have 4 purplish petals. The leaves are arranged in groups of 6 along the stem. It doesn't really grow upward and stays close to the ground.

It looks a little like bedstraw, but I can't find the exact name.